The present disclosure relates to a separator including a single or double conical drum rotatably mounted on one of its axial ends about a vertical axis of rotation.
Separators of this type have been known for a long time. As a rule, fluid outlets are provided with so-called centripetal pumps in which the effect is that the rotational energy of the entering fluid is converted to a back pressure in the outlet pipe. Such centripetal pumps have been successful. In particular, it is possible to vary the existing back pressure by throttling, thereby varying the separation zone in the drum or the radius of the separating drum in the drum over a certain area A. It is known to assign centripetal pumps to both fluid outlets.
A known three-phase separator is illustrated in FIG. 3. If a centripetal pump is assigned to one or both of the two fluid discharges or outlets from the drum and the additional outlet is constructed in a nozzle-type manner, a delta LP area is formed, within which the centripetal pump permits a displacement of the separation zone in the drum by throttling. See, for example, International Patent Document WO 86/01436. Here the area of displaceability of the separation zone is still relatively small, and it is also not easily possible to displace the separation zone in the area sufficiently rapidly. The displacement also does not always lead to stable process conditions because the variation of the throttling of the centripetal pump outlets will influence several parameters of the process simultaneously.
Concerning the state of the art, U.S. Pat. No. 4,417,885 A, Japanese Patent Document JP 03 13 54 58 A, and German Patent Documents DE 1 140 144 and DE 23 22 491 A1 are noted. U.S. Pat. No. 4,417,885 A shows a fluid seal on a centripetal-pump-type outlet of a separator. International Patent Documents WO 2006/096113 and WO 92/07658 also suggest the feeding of pressure in the inlet area of a centrifuge.
Another three-phase separator is known from German Patent Document DE 10 2005 021 331.6. This document suggests a separator having a separator drum, which has an inlet tube for a product to be processed, at least two fluid outlets for a lighter phase and a heavier phase, solid material discharge openings, preferably in the area of its largest inner circumference, a separation pan assembly arranged in the separator drum and an adjustable throttling device outside the drum. The adjustable throttling device has a ring plate or orifice plate and is designed for displacing the fluid radius, to which the heavy phase extends in the drum, by changing the outflow cross-section for the heavy fluid phase by throttling. This construction was found to be successful, but a further constructive simplification is desirable.
The present disclosure relates to a further development of a separator of the above-mentioned type such that, in a constructively simple manner, it is possible to displace the separation zone within the drum over a sufficiently large radial area during the operation. In such a case, a good adjustability of the location of the separation zone is possible.
The present disclosure relates to a separator that includes a separator drum having a conical interior and rotatably mounted at an axial end about a vertical axis of rotation. A rotating spindle located at either a lower or upper end of the separator drum and is configured to drive the separator drum. The rotating spindle is disposed in an oscillating manner about a hinge point. Further included is a supply tube for a product to be processed and at least two fluid outlets. One fluid outlet is for a light phase and one fluid outlet for a heavy phase. A solid material discharge opening is located in an area of the separator drum's largest inner circumference. Also included is a separation pan assembly and a pressure chamber configured to be acted upon by a fluid to change a location of a separation zone between the light phase and the heavy phase.
In accordance with the present disclosure, a very good controllability of the process is obtained and, in the process, a very good automatic controllability of the location of the separation zone, also called E-line. At the same time, the constructive setup is relatively simple.
In accordance with the present disclosure, it is possible to compensate for changes of product quantities, for example, phase relationship, as well as changes of the product quality, for example, the density, and nevertheless keep the separating or E-line almost constant.
It is known that, in the case of a centrifugally acting separator, the pressure may decrease in the center, whereby pressures P1 and P2 are lowered. As a function of the fluid properties, the pressures P1 and P2, as well as the process temperature, the one or both fluid phase(s) may start to evaporate or boil. This may prevent a good separation because gas bubbles or foam may form in the fluid.
In some cases, such as some petroleum crude oils, carbon dioxide may also evolve, which may result in an increase of the pH value in the crude oil and may lead to the formation of calcium naphthenates and other compounds. This may have a very disadvantageous effect on the process stability in the drum.
In addition, the steam pressure of the two fluids may differ, which, because of the difference of the chamber pressures P1 and P2, may result in a displacement of the E-line.
Maintaining pressure on the fluid phases, which is higher than the steam pressure of the corresponding fluids, may avoid these disadvantageous effects and may also be utilized for controlling. For example, automatically controlling the location of the E-line by varying the differential pressure between P1 and P2. The present disclosure also relates to a process in which, by a separator according to the present disclosure, the work takes place according to a step that includes maintaining a pressure on the fluid phases which is higher than the steam pressure of the corresponding fluids.
The separator, according to the present disclosure, is extremely suitable for the most varied three-phase separating tasks. For example, it is suitable for processing crude oil, in which the crude oil is cleansed from solid material and water and is separated from the crude oil. It is also suitable for the treatment of diluted soluble oil, by which water is separated from oil and cleansed from solid material.
On the one hand, it is within the scope of the present disclosure that the fluid outlet for the lighter phase (LP) is provided with a centripetal pump. As an alternative or in addition, the fluid outlet for the heavier phase (HP) may also be provided with a centripetal pump but a centripetal pump is not provided in the embodiment as depicted in FIG. 1.
In accordance with the present disclosure, there are various options for the arrangement of the pressure chamber. Thus, the pressure chamber may be arranged in front of one of the fluid outlets or both fluid outlets. One of the pressure chambers or the one pressure chamber may, however also be constructed in the area of an inlet chamber.
There are other features of the present disclosure disclosed herein.
Other aspects of the present disclosure will become apparent from the following descriptions when considered in conjunction with the accompanying drawings.